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51.
Anti-HEV antibodies were detected in animals from abattoir and in farms from northeast Brazil. Our results suggest that HEV is highly disseminated in the swine population and might present a great risk to animal handlers and for consumption of raw or undercooked meat and meat products in northeast Brazil.  相似文献   
52.
This study examines the impact of building design on privacy in two office environments at Gulfstream Aerospace Corporation, Inc., U.S.A. The findings offer a range of design resources that Facility Management at Gulfstream can utilize to manage privacy for their office workers. In a broader context, the theoretical considerations presented in this study, though still in their formative stage, offer additional insight into what office workers may think about privacy in the work environment. These theoretical considerations have far reaching implications for design professionals, and pending further research may prove cost effective.  相似文献   
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Quantifying the human health benefits of curbing air pollution in Shanghai   总被引:1,自引:0,他引:1  
Urban development in the mega-cities of Asia has caused detrimental effects on the human health of its inhabitants through air pollution. However, averting these health damages by investing in clean energy and industrial technologies and measures can be expensive. Many cities do not have the capital to make such investments or may prefer to invest that capital elsewhere. In this article, we examine the city of Shanghai, China, and perform an illustrative cost/benefit analysis of air pollution control. Between 1995 and 2020 we expect that Shanghai will continue to grow rapidly. Increased demands for energy will cause increased use of fossil fuels and increased emissions of air pollutants. In this work, we examine emissions of particles smaller than 10 microm in diameter (PM10), which have been associated with inhalation health effects. We hypothesize the establishment of a new technology strategy for coal-fired power generation after 2010 and a new industrial coal-use policy. The health benefits of pollution reduction are compared with the investment costs for the new strategies. The study shows that the benefit-to-cost ratio is in the range of 1-5 for the power-sector initiative and 2-15 for the industrial-sector initiative. Thus, there appear to be considerable net benefits for these strategies, which could be very large depending on the valuation of health effects in China today and in the future. This study therefore provides economic grounds for supporting investments in air pollution control in developing cities like Shanghai.  相似文献   
55.
The modified three-step sequential extraction procedure proposed by the Community Bureau of Reference (or Bureau Communautaire de Reference, BCR) was used to predict trace element mobility in soils affected by an accidental spill comprising arsenopyrite- and heavy metal-enriched sludge particles and acid waste waters. The procedure was used to obtain the distribution of both the major (Al, Ca, Fe, Mg, and Mn) and trace elements (As, Bi, Cd, Cu, Pb, Tl, and Zn) in 13 soils of contrasting properties with various levels of contamination and in the sludge itself. The distributions of the major elements enabled us to confirm the main soil fractions solubilized in each of the three steps, and, in turn, to detect the presence of pyritic sludge particles by the high Fe extractability obtained in the third step. Cadmium was identified as being the most mobile of the elements, having the highest extractability in the first step, followed by Zn and Cu, Lead, Tl, Bi, and As were shown to be poorly mobile or nonmobile. In the case of some of the trace elements, the residual fractions decreased at higher levels of contamination, which was attributed to the anthropogenic contributions to the polluted samples. Comparison with soil-plant transfer factors, calculated in plants growing in the affected area, indicated that a relative sequence of trace element mobility was well predicted from data of the first step.  相似文献   
56.
Synoptic data on concentrations of sediment-associated chemical contaminants and benthic macroinfaunal community structure were collected from 1,389 stations in estuaries along the U.S. Atlantic and Gulf of Mexico coasts as part of the nationwide Environmental Monitoring and Assessment Program (EMAP). These data were used to develop an empirical framework for evaluating risks of benthic community-level effects within different ranges of sediment contamination from mixtures of multiple chemicals present at varying concentrations. Sediment contamination was expressed as the mean ratio of individual chemical concentrations relative to corresponding sediment quality guidelines (SQGs), including Effects Range-Median (ERM) and Probable Effects Level (PEL) values. Benthic condition was assessed using diagnostic, multi-metric indices developed for each of three EMAP provinces (Virginian, Carolinian, and Louisianian). Cumulative percentages of stations with a degraded benthic community were plotted against ascending values of the mean ERM and PEL quotients. Based on the observed relationships, mean SQG quotients were divided into four ranges corresponding to either a low, moderate, high, or very high incidence of degraded benthic condition. Results showed that condition of the ambient benthic community provides a reliable and sensitive indicator for evaluating the biological significance of sediment-associated stressors. Mean SQG quotients marking the beginning of the contaminant range associated with the highest incidence of benthic impacts (73–100% of samples, depending on the province and type of SQG) were well below those linked to high risks of sediment toxicity as determined by short-term toxicity tests with single species. Measures of the ambient benthic community reflect the sensitivities of multiple species and life stages to persistent exposures under actual field conditions. Similar results were obtained with preliminary data from the west coast (Puget Sound).  相似文献   
57.
Droughts can have severe negative effects on the environment, society and economy. The drought of 2001–2002 caused severe strain on economic and social activities in western Canada, particularly on rural communities through changes in water resources. This paper examines physical and social vulnerabilities and associated adaptation measures undertaken and the adaptive capacity in communities in the South Saskatchewan River Basin, Canada. Although all of these communities were exposed to the 2001–2002 drought, they had different levels of impacts, resulting in different types of drought adaptation measures, some due to experience with previous droughts and some in response to the 2001–2002 drought. Communities with unreliable water supply were the most vulnerable to these droughts. This vulnerability resulted in historic adaptations being implemented (e.g., Hanna, Alberta) and re-active adaptations (e.g., Cabri, Saskatchewan). It is important to examine the effectiveness of the current adaptive strategies to cope with more extensive and extended drought situations. First Nation communities, such as the Kainai Blood Indian Reserve, have many social and environmental issues but the impacts from the drought were minor. The Reserve had implemented economic changes in the late 1980s to make it less vulnerable to drought but resulted in negative impacts to the Reserve’s social health. It is imperative to determine how vulnerable First Nation communities are and will to improve future adaptive capacity. This paper provides a snap shot view of how Canadian Prairie Communities have adapted to drought and how vulnerable they are to future drought situations.  相似文献   
58.
Increasing pulp industry production has generated additional solid waste (i.e. biological sludge, dregs, etc.) and therefore an increasing disposal problem. On the other hand, composting is emerging as an interesting alternative for the disposal of residues. The objective of this study was to evaluate the physical and chemical properties of sludge, dregs and bark and the effect on their initial conditioning stage prior to composting, using pine chips as bulking agent. After their characterization, these solid wastes were combined in different mixture proportions defined by a 32 experimental design based on the response surface methodology (RSM), in which 18 observations were required for the independent variables (dregs and bark) and the C: N ratio, moisture content and pH were the dependent variables. The characterization indicated that the dregs have alkaline properties with the presence of some essential plant nutrients, such as phosphorous (0.37%), potassium (0.76%), magnesium (1.4%) and calcium (27%). The combination of the macronutrients (phosphorous: 0.39%, potassium: 0.24%, calcium: 1.7%, magnesium: 0.44%) and micronutrients such as ferrous material (0.47%) and zinc (0.12%) found in the sludge suggest a promising alternative despite the potential problem due to the high pH of the dregs. The RSM design indicated a feasible region that satisfied the optimal dregs: bark ratio of 0.25 without exceeding the addition of 12.5% dregs, due to the alkaline properties of these inorganic wastes and the quadratic influence over the C:N ratio. The experimental results indicated that the composting process of dregs, bark and sludge is technically suitable, although the use of a rapidly available C source needs to be evaluated.  相似文献   
59.
During austral summer 2006, experiments were carried out to evaluate the effects of ultraviolet radiation (UVR, 280–400 nm) on carbon fixation of natural phytoplankton assemblages from Patagonia (Argentina). Surface water samples were collected (ca. 100 m offshore) at mid morning using an acid-cleaned (1 N HCl) dark container. The short-term impact of UVR (measured as radiocarbon incorporation) was immediately assessed by exposing samples to three artificial illumination treatments: PAR (400–700 nm), PAR + UV-A (320–700 nm), and PAR + UV-A + UV-B (280–700 nm). Pico-nanoplankton characterized the assemblages, and taxon-specific pigment fingerprinting combined with CHEMTAX and supplemented with microscopic observations showed varied proportions of diatoms, chlorophytes, and cyanobacteria throughout January–February 2006. Photosynthetic efficiency, as assessed through assimilation numbers, was high [between 4.4 and 10.4 μg C (μg chl-a)−1 h−1], and it was probably favored by the supply of inorganic nutrients from the Chubut River. UVR-induced photoinhibition appeared to be related to the taxonomic composition: in general, higher photoinhibition was observed when diatoms dominated, whereas this was lower when samples were dominated by chlorophytes. Our data suggest that xanthophyll pigments might have provided only limited protection in these already highlighted acclimated assemblages.  相似文献   
60.
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